Burner



March 8, 1966 R. VON LINDE ETAL 3238990 BRNER Filed March 13, 1964 2 Sheets-Sheet 2 United States Patent O 3,238,990 BURNER Robert von Linde, 56 Akiliudastrasse, Graefelfing, near Munich, Germany, and Engen P. Herbutt, Munich- Grosshadern, Germany; said Herbutt assignor to said von Linde Filed Max. 13, 1964, Sex. N0. 351,704 Claims priority, application Germany, Mal. 29, 1963,

44,496 12 Claims. (C1. 1ss-1 -gas rr1ixture is a Valuable endothermic gasification medium which, by reason of its contents of carbonic acid and water vapor, prepares the fuel injected into the returned gas mixture and/01' finely distributed therein, that is, converts or transforms the sarne into a readily combustible gas mixture which now burns with the combustion air added thereto completely fr'ee of soot and smoke and with a clear, short fiame. Furthermore, it has been found that the burners of th.is type are not only useful for the generation of heat in furnaces with stoichiornetric supply of combustion air or with slight air ex-cess by reason cf the superior flame formation thereof, but can be operated even under considerable air shortage and therewith can be used for the production of mixtures effective as reducing agents which, by reason of the high content in carbon monoxi-de and/er hydrogen may be used, for example, as protective gases or similar purposes in industrial ovens or furnces cf all types. Thus, strongly reducing exhaust gases could be produced from heating oils and also from propane and butane. The burrier is equally suited for the preparation of powdered fuels. The return ducts o1 channels needed in the burners of this type, which discharge into a special mixing charmber separate from the air supply and are provi-ded with means for the distribution and possibly also for the atomization of the fuel capable of flowing, render diflicult the Inanufa'cture -of such burners. In particular, it has not been possible heretofore to so construct burners f this type that they can be easily manufactured and readily disassembled for purposes of cleaning and exchanging individual component parts thereof.

These difficulties are avoided by the present invention in that the burner consists cf several structural parts arranged one behind the other and sealed With respect one another by seating surfaces, which structural parts complement one another, 011 the one band, forming channels or ducts for the returning gases and, on the other, forming passages for the supply of combustion air. A particularly appropriate embodiment of the burner in accordance with the present invention essentially comsists in that a housing part to -be flangedly connected 10 the combustion charn.ber and serving as bearing socket, the bottom of which forms the forward end wall of the combnstion chamber and which is provided with a central aperture for the accomrnodation of a driving 01 mixing nozzle as well as with lateral apertures for the suckedback partial quantity of the combustion gas mixture, is closed by a cover which =carries the fuel supply, and in that a further hollow structural part is accommodated within the hollow space defined -by this cover and the housing part serving as bearing socket, which further hollow structural part divides or separates with respect to each other the hollow space chambers needed for the mixture components to be'returned and f0r the supply of 3,238,990 Patented Maar. 8, 1966 lce the combustion air. It is achieved by this construction that only a single sealing gap is present on the outside of the burner.

Accordingly, it is an object of the present invention to provide a burner of the type described hereinabove which eliminates by extremely simple rneans the shortcomings and disadvantages encountered in the prior art constructions.

It is another object of the present invention to provide a burner of the type described above and constituted by several separately made parts, which may be readily manufactured and easily assembled as wel1 as disassembled when necessary.

Another object cf the present invention resides in the provision cf a burner construction of the type described above which is not only relatively inexpensive as regard's the manufacture and assernbly, but also minirnizes difi'iculties With respect to the sealing of the various parts thereof.

These and other objects, features and advantages cf the present invention will become more obvious from the following description When taken in connection With the accompanying drawing which shows, for purposes of illustration only, severalembodiments in accordance With the present invention, and Wherein FIGURE 1 is an elevational view of a housing part serving as bearing socket, taken in the direction of the arrows I in FIGURE 2;

FIGURE 2 is a cross-sectional view through the bearing socket of FIGURE 1, taken along line IIII 0f FIGURE 1;

FIGURE 3 is a partial cross-sectional view through the complete burner taken along line III--III of FIG- URE l, whereby a spark plug 30 has been inserted in the place of the plug or stopper 29;

FIGURE 4 is a partial cross-sectional view, similar to FIGURE 3, thro'ugh a modified embodiment o-f a bu1ner in accordance with the present invention, and

FIGURE 5 is a partial cross-sectional view, similar to FIGURES 3 and 40, through still a further modified embodiment in accordance With the present invention.

Referring now to the drawing wherein like reference numerals are used throughout the various views to designate like parts, reference numeral 10 designates in the illustratetd embodiments a conventional combustion chamber which is closed off at the frontend thereof (FIGURES 3 to 5) by a housing part 12 provided with a flange 11, which housing part 12 forms a bearing er Support socket for the remaining p'arts of the burner. The bottom 14 of this socket 12 which forms the forward end Wall of the combustion chamber 10, contains a centrally arranged hollow space 15 forming an aperture which is constituted by a short tubular member er short piece of pipe 16. Laterally of this short piece of pipe 16, the bottom 14 is provided with several projections o1 raised portions 17 which are provided With hollow spaces 01' apertures 18 open on =b0th sides thereof. These hollow spaces or passages 18 each forrn a first section of the return channels er ducts which discharge in a plane sealing surface within the housing 12.

Stub-like raised portions 19 are sealingly supported against this sealing surface; these raised portions 19 are seated at the bottom of a cap-like housing insert 20 and contain ducts or channels corresponding to the channels 18 which form each a further section of the return ducts or channels terminating in the hollow space of the housing insert 20. The corn'bustion air which is introduced into the housing 12 through a lateral connecting nipple 13 is able to flow or pass through between the raised portions 19 into the relatively shallow, hollow space 01' passage 22 defined by the bottom 14 of the bearing socket 12 and by the bottom of the housing insert 20 and from there 3 along the outer Wall of a mixing nozzle 21, which is seated at the botton1 of the housing insert 20, into the hollow space 15. A pressure drop occurs thereby at the orifice of the nozzle 21 which efiects that hat combustion gas mixture is sucked out of the combustion chamber 10 by way of return channels 18 and the hollow space of the cap-shaped housing insert 20 into this nozzle 21 along the path indicated in the drawing in dash and dot lines.

In the ernbodiment according to FIGURE 3, liquid fuel is injected into this mixture in a finely distributed condition by an atomizer nozzle 24 of conventional comstruction which is inserted axially into a cover 25 tightly closing the housing socket 12. In this cover 25, which is constructed in a cap-like manner and is secured at the socket 12 by screws 28, is arranged a partition wall 26 provided With a central aperture 27 through which is supplied the atornized liquid fuel to the combination gas mixture flowing toward the mixing nozzle 21. This aperture 27 thus also ofiers the possibility to displace the burner stock discharging into the atomizer nozzle 24 toward the mixing nozzle 21 and thus to adjust the quantity of returned combustion gas mixture flowing toward this nozzle 21 t the prevailing requirements.

Spark plugs 30 of conventional construction may be utilized for the ignition of the supplied mixture of fuel and combustion air, as illustrated in the drawing. For the installation of these spark plugs 30, several threaded bores are provided within the conical housing part of the bearing socket 12 which discharge obliquely into the combustion chamber 10. It is thereby recommended, as may be seen particularly from FIGURE 1, to arrange more threaded bores distributed over the housing circumference than are needed for the spark plugs. The location and arrangernent of the ignition places can then be readily matched and adapted to the existing structural conditions. The threaded bores not needed in a given case for the insertion of spark plugs can then be closed oif by simple threaded plugs or stoppers 29 insofar as they are not to be used for the accommodation of measuring and observation devices.

The burner according to the present invention may, of course, also be operated with gaseous fuel. For that purpose, as may be seen from FIGURE 4, the atomizer nozzle 24 is replaced by a suitable gas distributor, preferably by a pipe or tubular piece 33 closed at the and face thereof and provided With outflow apertures 34 discharging laterally into the cap-shaped hollow space of the cover 25. In order to achieve a good mixture formation, the partition Wall 26 preferably now provided in the rim zone thereof with sieve-like perforations 37. As further shown in FIG- URE 4, it may be desirable to connect a mixing pipe 36 to the rear, that is, downstream of the tubular piece 16.

As already mentioned above, the burner according t0 the present invention is also suitable for the manufacture of reducing gas mixtures. The mixture conversion thereby has to take place under a shortage 01' lack of air. Hewever, under such operating conditions, the quantities of heat necessary for the conversion or reaction are not liberated by the supplied fuel, particularly if strongly reducing utilization gases are to be obtained under correspondingly large air shortage. In these cases, it is therefore necessary to supply additional heat to the process.

An arrangement particularly suitable for -this operation is illustrated in FIGURE 5. In that case, the combustion air is supplied to the burner, in which the main structural parts 12 and 25 are again utilized as in connection With the other embodiments, by means of a line 42 extending centrally through the combustion space and provided with an electric heating system 41 jacketing or surrounding the same. The conically shaped end face 43 of the line 42 discharges or terminates in a bucket 01' cup-shaped insert body 40. This insert body 40, which is arranged at the partition Wall 26, firstly serves for the deflection of the produced Warm air stream. The internal Wall surfaces of this hollow body 40 form toge herwith the external surfaces of the pipe end 43 an annularly-shaped driving nozzle, whereas the outer Wall surfaces of the hollow insert 40 form, together with the central hollow space 15 within the housing socket 12, an annnlarlyshaped. mixing nozzle for the supply of the mixture comsisting of the returned combustion gas components and fuel. In this application, the connecting nipple 13 may be utilized either for the supply of a further working medium having flow characteristics and useful for the operation cf the installation or, as illustrated, may be closed oft by a closure plug 49.

While We have shown and described several ernbodiments in accordance with the present invention, it is understood that the sarne is not limited thereto, but is susceptible of numerous changes and modifications as known to a person skilled in the art, and WC, therefore, do not wish to be limited to the -details shown and described herein, but intend to cover all such changes and modifications as are encompassed by the scope of the appended claims.

We claim:

1. A burner assembly, comprising combustion chamber means,

nozzle means having an inlet ortion and an outlet portion,

air channel means to deliver combustion air adjacent to said outlet portion of said nozzle means to produce a substantial suction within said nozzle means at said outlet ortion,

return channel means to conduct combustion gases from said combustion chamber means to said inlet portion 0f said nozzle means in response to the suction,

fuel supply means to deliver fuel to the combustion gases and mix the fuel with the combustion gases prior to the fuel and gases reaching said outlet portion of said nozzle means,

and a plurality of structural parts arranged serially With respect to one another and sealed with respect t0 each other, and provided with cornplementary means constituting in part said return channel means and said air channel means.

2. A burner assembly comprising:

combustion chamber means,

nozzle means having an inlet portion and an outlet portion,

air channel means to deliver combustion air adjacent t0 said outlet portion of said nozzle means to produce a substantial suction within said nozzle means at saidl outlet portion,

return channel means to conduct combustion gases from' said combustion chamber means to said inlet portion of said nozzle means in response to the suction,

fuel supply means to deliver fuel to the combustion gases and mix the fuel with the combustion gases prior to the fuel and gases reaching said outlet portion of said nozzle means,

a plurality of structural parts arranged serially with respect to one another and sealed with respect to each other, and provided with cornplementary means constituting in part said return channel means and said air channel means,

a first one of said parts being a housing part serving as a bearing socket and flangedly connected With the combustion charnber means, said first part being provided with a bottom forming the forward end Wall of said combustion charnber means and being providedl With a central aperture for the accommodation 0f said nozzle means and With lateral apertures com-' prising in part said return channel means for the: return of the combustion gases,

a second one of said parts being forn'1ed by a COVBI" closing said first housing part and carrying said fuel supply means,

and said c0ver and said first housing part defining therebetween a second chamber, and a fumlher hollow Structurl art @Qll5fitllfiflg a third one= Qf said m 5. accommodated in said second chamber, which divides said second chamber to forrn in part therein said air channel means and said return channel means.

3. A burner assembly, comprising cornbustion chamber means,

nozzle means having an inlet portion and an outlet portion,

air channel means to deliver combustion air adjacent to said outlet portion of said nozzle means t produce a substantial suction Within said nozzle means at said outlet portion,

return channel means to conduct combustion gases from said combustion chamber means to said inlet portion of said nozzle means in response to the suction,

fuel supply means to deliver fuel to the combustion gases and mix fuel With the combustion gases prior to the fuel and gases reaching said outlet portion cf the nozzle means,

a plurality of structural parts arranged serially With respect to one another and sealed with respect to each other, and provided with complementary means constituting in part said return channel means and said air channel means,

a first one of said parts being a housing part serving as a bearing socket and flanged-ly connected With the combustion chamber means, said first part being provided with a bottom forming the forward end wall of said combustion chamber means and being provided with a central aperture for the accommodation of said nozzle means and With lateral apertures comprising in part said return channel means for the return of the combustion gase,

a second one of said parts being formed by a cover closing said first housing part and carrying said fuel supply means,

said cover and said first housing part defining therebetween a second chamber,

a further hollow structural part in the form of a caplike insert and constituting a third one of said parts accornmodated in said second chamber, which divides said second chamber to form in part therein said.air channel means and said return channel means,

said cap-like insert rnember having a bottom facing said bearing socket,

said nozzle means being carried by the bottom of said cap-like insert in communication With said central aperture in said bearing socket,

the bottorn of said cap-like insert being provided laterally of said nozzle means with hollow raised portions which adjoin in a sealing manner with a bottom cf said bearing socket in alignrnent with said lateral apertures to form a further section of said return channel means comrnunicating With said inlet portion of said nozzle means, while leaving therebetween passages crossing said return channel means and comprising in part said air channel means.

4. A burner assembly, cornprising combustion chamber means,

nozzle means having an inlet portion and an outlet portion,

air channel means to deliver combustion air adjacent to said outlet portion of said nozzle means to produce a substantial suction within said nozzle means at said outlet portion,

return channel means to conduct combustion gases frorn said cornbustion chamber means to said inlet portion of said nozzle means in response to the suction,

fuel supply means to deliver fuel to the combustion gases and mix the fuel with the combustion gases prior to the -fuel and gases reaching said outlet portion of said nozzle means,

a plurality of structural parts arranged serially With respect to one another and sealed With respect to each other, and provided with complementary means con- 6 stituting in part said return channel means and said air channel means,

a first one of said parts being a housing part serving as a bearing socket and flangedly connected With the combustion chamber means, said first part being provided With a bottorn forming the forward end Wall of said combustion chamber means and being provided With a central aperture for the accommodation of said nozzle means and with lateral apertures comprising in part said return channel means for the return of the cornbustion gases,

a second one of said parts being formed by a cover closing said first housing part and carrying said fuel supply means,

said cover and said first housing part defining therebetween a second chamber,

a further hollow structural part in the form of a Caplike insert and constituting a third one of said parts accommodated in said second chamber, which divides said second chamber to forrn in part therein said air channel means and said return channel means,

said cap-like insert member having a bottom facing said bearing socket,

said nozzle means being carried by the bottom of said cap-like insert in communication with said central aperture in said bearing socket,

the bottom of said cap-like insert being provided laterally of said nozzle means with hollow raised portions which adjoin in a sealing manner With a bottom 0f said bearing socket in alignment With said lateral apertures to form a further section of said return channel means communicating With said inlet portion of said nozzle means, while leaving therebetween passages crossing said return channel means and comprising in part said air channel means,

said nozzle means having a venturi Shape,

and an annular gap between said central aperture of said bearing socket bottom and said nozzle means to forrn the terminal end of said air channel means and distribute the air around said outlet portion of said nozzle means to prodnce the suction.

5. A burner assernbly, comprising combustion chamber means,

nozzle means having an inlet portion and an outlet portion,

air channel means to deliver combustion air adjacent to said outlet portion of said nozzle means t0 produce a substantial suction within said nozzle means at said outlet portion,

return channel means to conduct combustion gases from said combustion chamber means to said inlet portion of said nozzle means in response to the suction,

fuel supply means to deliver fuel to the combustion gases and mix the fuel with the combnstion gases prior to the fuel and gases reaching said outlet portion of said nozzle means,

a plurality of structural parts arranged serially with respect to one another and sealed with respect to each other, and provided with complementary means constituting in part said return channel means and said air channel means,

a first one of said parts being a housing part serving as bearing socket and flangedly connected with the combustion chamber means, said first part being provided With a bottom forming the forward end Wall of said combustion chambefmeans and being provided With a central aperture for the accornrnodation of said nozzle means and With lateral apertures comprising in part said return channel means for the return of the combustion gases,

a second one of said parts being formed by a cover closing said first housing part and carrying said fuel supply means,

said cover and said first housing part defining therebetween a second chamber,

a further hollow structural part in the forrn of a (raplike insert and constituting a third one of said parts accommodated in said second chamber, which divides said second chamber to form in part therein said air channel rnez1ns and said return channel means, rnean,s

said -cap-like insert mernber having a bottom facing said bearing socket,

said nozzle means being carried by the bottom of said cap-like insert in cornmunication with said central aperture in said bearing socket,

the bottom of said cap-like insert being provided laterally of said nozzle means with hollow raised portions which adjoin in a sealing manner with a bottom of said bearing socket in alignment with said lateral apertures to form a further section of said return channel rneans communicating With said inlet portion of said nozzle means while leaving therebetween passages crossing said return channel means and comprising in part said air channel means,

and the outer walls of said first housing part being provided with a connecting nipple communicating with said passages and adapted to be used for the supply of combustion air.

6. A burner assembly, comprising combustion chamber means,

nozzle rneans having an inlet portion and an outlet portion,

air channel means to deliver combustion air adjacent to said outlet portion f said nozzle means to produce a substantial suction within said nozzle means at said outlet portion,

return channel means to conduct combustion gases from said combustion chamber means to said inlet portion of said nozzle means in response to the suction,

fuel supply rneans to deliver fuel to the combustion gases and rnix the fuel With the combustion gases prior to the fuel and gases reaching said outlet portion cf said nozzle means,

a plurality of structural parts arranged serially with respect to one another and sealed with respect to each other, and provided with cornplementary means constituting in part said return channel means and said air channel means,

a first one of said parts being a housing part serving as a bearing socket and flangedly connected with said combination charnber means, said first part being provided with a bottom forming the forward end wall of said combustion chamber means and being provided with a central aperture for the accommodation of said nozzle means and with lateral apertures comprising in part said return channel means for the return of the combustion gases,

a second one of said parts being formed by a cover closing said first housing part and carrying said fuel supply means,

said cover and said housing part defining therebetween a second chamber,

and said cover being constructed in a cap-like manner,

a partition wall subdividing said second chamber and provided with a least one aperture.

7. A burner assembly, comprising combustion chamber means,

nozzle means having an inlet portion and an outlet portion,

air channel means to deliver combustion air adjacent to said outlet portion of said nozzle means to produce a substantial suction within said nozzle means at said outlet portion,

return channel rneans to conduct combustion gases from said combustion chamber means to said inlet portion of said nozzle means in response to the suction,

fuel supply means to deliver fuel to the combustion gases and mix the fuel with the combustion gases prior to the fuel and gases reaching said outlet portion of said nozzle means,

a plurality of structural parts arranged serially with respect t0 one another and sealed with respect to each other, and provided with complementary means constituting in part said return channel means and said air channel means,

a first one of said parts being a housing part serving as a bearing socket and flangedly connectecl with the combustion chamber means, said first part being provided With a bottom forming the forward end wall of said combustion chamber means and being provided with a central aperture for the accommodation of said nozzle means and with lateral apertures comprising in part said return channel means for the return of the combustion gases,

a second one of said parts being formed by a cover closing said first housing part and carrying said fuel supply means,

said cover and said first housing part defining therebetween a second chamber, and a further hollow structural part constituting a third one of said parts accommodated in said second chamber, which divides said second chamber to form in part therein said air channel means and said return channel'means,

the outer walls 0f said first housing parts, serving as said bearing socket, being provided with a connecting nipple communicating with said passages and adapted to be used for the supply of combustion air,

said cover being constructed in a cap-like manner,

and a partition wall subdividing said second chamber and being provided with at least one aperture.

8. A burner assernbly, cornprising combustion chamber means,

nozzle means having an inlet portion and an outlet portion,

air channel means to deliver combustion air adjacent to said outlet portion of said nozzle means to produce a substantial suction within said nozzle means at said outlet ortion,

return channel means to conduct combustion gases from said combustion chamber means to said inlet portion of said nozzle means in response to the suction,

fuel supply means to deliver fuel to the combustion gases and mix the fuel with the combustion gases prior to the fuel and gases reaching said outlet portion of said nozzle means,

a plurality of structural parts arranged serially with respect to one another and sea]ed With respect to each other, and provided with complementary means constituting in part said return channel means and said air channel means,

a first one of said parts being a housing part serving as a bearing socket and flangedly connected with said combustion charnber rneans, said first part being provided With a bottom forming the forward end wall of said combustion charnber means and being provided with a central aperture for the accomrnodation of said nozzle means and With lateral apertures comprising in part said return channel means for the return of the combustion gases,

a second one of said parts being formed by a cover closing said first housing part and carrying said fuel supply means,

said cover and said housing part defining therebetween a second chamber,

said cover being constructed in a cap-like manner,

a artition wall subdividing said second chamber and provided with at least one aperture,

said partition wall being axially between said nozzle means and said fuel supply means,

said fuel supply means including an atomizer nozzle means,

and said aperture in said artition wall being centrally 9', located for the -passage of the fuel mist discharged from said atornizer nozzle means.

9. A burner assembly, comprising combustion chamber means,

nozzle means having an inlet-portion and an outlet portion,

air channel means to deliver combustion air adjaicent to said outlet portion cf said nozzle means to produ ce a substantial suction within said nozzle means at said outlet portion,

return channel means to conduct combustion gases from said cornbustion chamber means t said inlet portion of said nozzle means in response to the suction,

fuel supply means to deliver fuel to the combustion gases and rnix the fuel with the combus tion gases prior to the fuel and gases reaching said outlet portion cf said nozzle means,

a plurality of structural parts arranged serially With respect to one -another and sealed with respect to each other, and provided with complemehfary means constituting in part said return channel means and said air channel means,

a first one of said parts being a housing part serving as a bearing socket and flangedly connegted with said combustion chamber means, said first part being provided With a bottom forming the fotward end wall of said combustion chamber means and being provided with a central aperture forthe accommodation of said nozzle means and with lateral apartures comprising in part said return channel means for the return of the combustion gases,

a second one of said parts being formed by a cover closing said first housing part and carrying said fuel supply means,

said cover and said housing part defining therebetween a second chamber,

said cover being constructed in a cap-like manner,

a partition wall subdividing said second chamber and provided With at least one aperture,

and a plurality of gas discharge apertures provided in the rim zone of said artition wall for the passage therethrough of -a gaseous fuel.

10. A burner assembly comprising combustion chamber means,

nozzle means having an inlet portion and an outlet portion,

air channel means t0 deliver cornbustion air adjacent to said outlet portion of said nozzle means to produce a substantial suction within said nozzle means at said outlet portion,

return channel means to conduct combustion gases from said combustion chamber means to said inlet portion of said nozzle means in response to the suction,

fuel supply means to deliver fuel to the combustion gases and mix the fuel with the combustion gases prior to the fuel and gases reaching said outlet portion of said nozzle means,

a plurality of structural parts arranged serially with respect to one another and sealed with respect to each other, and provided with complementary means constituting in part said return channel means and said air channel means,

a first one of said parts being a housing part serving as a bearing socket and flangedly connected with the cornbustion chamber means, said first part being provided with a bottom forming the forward end wall of said combustion chamber means and being provided with a central aperture for the accommodation of said nozzle means and With lateral apertures comprising in part said return channel means for the return of the combustion gases,

a second one of said parts being formed by a cover 10 closing said first housing part and carrying said fuel supply means,

said cover and said firsthousing part defining therebetween a second chamber,

a Partition wall between said first housing part and said cover, and a substantially cup-shaped insert carried by said partition wall,

and said air channel means inclu'ding conduit means within said combustion chamber means and terminating in said cup-shaped insert member which-deflects the combustion air stream, the rim portions of said insert rnember forming With the external surfaces of said conduit means, an annular driving nozzle and with the central apertu-re of the bearing Socket an annularly shaped suction gap forming said nozzle means.

11. A burner assembly comprising:

combustion cham-ber means,

nozzle means having an inlet portion and an outlet portion,

air channel means to deliver combustion air adjacent to said outlet portion of said nozzle means to produce a substantial suction within said nozzle means at said outlet portion,

retu-rn channel means to conduct combustion gases from said combustion chamber means to said inlet portion of said nozzle means in response to the suction,

fuel supply means to deliver fuel to the cornbustion gases and mix the fuel With the combustion gases prior to the fuel and gases reaching said outlet portion of said nozzle means,

a plurality of structural parts arranged serially With respect to one another and sealed with respect to each other, and provided with complementary means constituting in part said return channel means and said air channel means,

and one of said parts being a housing part serving as a bearing socket, apertures distributed over the housing circumference being arranged within said housing part, said apertures including to the housing axis, extending in substantially radial planes and terminating in the combustion space, one of said apartures serving for the insertion of a spark plug and the others being adapted to be closed.

12. A burner assembly, comprising combustion ch-amber means,

nozzle means having an inlet portion and an outlet portion,

air channel means to deliver combustion air adjacent 10 said outlet portion c f said nozzle means to produce a substantial suction within said nozzle means at said outlet portion,

return chainnel means to conduct combustion gases from said combustion chamber means to said inlet portion of said nozzle means in response to the suction,

fuel supply means to deliver fuel to the combustion gases and mix the.iuel with the combustion gases prior to the fuel and gases reaching said outlet portion cf said nozzle means,

a plurality of structural parts arranged serially with respect to one another and sealed With respect to each .other, and provided with complementary means constituting in part said return channel means and said air channel means,

one of said parts being a housing part serving as a bearing socket and flangedly connected with said combustion chamber means, said housing part being provided with a bottom forming the forward end wall of said combu-stion charnber means and being provided with a central aperture for the accomrnodation of said nozzle means and with lateral apertures comprising in part said return channel means for the cornbustion gases to be returned,

another cf said parts being formed by a cover closing 1 1 said first housing part and carrying said fuel supply means, and a third one of said parts being accommodated between said first and second parts and serving to eifect a crossing cf said air channel means and said return channel means.

References Cited by the Examiner UNITED STATES PATENTS 10/1936 Morton 1581 X 12 2287245 6/1942 Hess 1587 FOREIGN PATENTS 1,111,865 11/1955 France.

JAMES W. WESTHAVER, E. G. FAVORS.

Assistant Examiners. 

1. A BURNER ASSEMBLY, COMPRISING COMBUSTION CHAMBER MEANS, NOZZLE MEANS HAVING AN INLET PORTION AND AN OUTLET PORTION, AIR CHANNEL MEANS TO DELIVER COMBUSTION AIR ADJACENT TO SAID OUTLET PORTION OF SAID NOZZLE MEANS TO PRODUCE A SUBSTANTIAL SUCTION WITHIN SAID NOZZLE MEANS TO SAID OUTLET PORTION, RETURN CHANNEL MEANS TO CONDUCT COMBUSTION GASES FROM SAID COMBUSTION CHAMBER MEANS TO SAID INLET PORTION OF SAID NOZZLE MEANS IN RESPONSE TO THE SUCTION, FUEL SUPPLY MEANS TO DELIVER FUEL TO THE COMBUSTION GASES AND MIX THE FUEL WITH THE COMBUSTION GASES PRIOR TO THE FUEL AND GASES REACHING SAID OUTLET PORTION OF SAID NOZZLE MEANS, AND A PLURALITY OF STRUCTURAL PARTS ARRANGED SERIALLY WITH RESPECT TO ONE ANOTHER AND SEALED WITH RESPECT TO EACH OTHER, AND PROVIDED WITH COMPLEMENTARY MEANS CONSTITUTING IN PART SAID RETURN CHANNEL MEANS AND SAID AIR CHANNEL MEANS. 